"I think Jim Comey deserves his chance to lay out to the American public his side of the facts," Warner told ABC News chief anchor George Stephanopoulos in an interview on "This Week" on Sunday morning. "How he was treated was pretty awful by the president."
Comey was invited to speak before the committee in a closed session Tuesday, but Warner told CNN on Friday that he declined the invitation.
Warner told ABC News that he doesn't "have the foggiest idea whether there are tapes or not" of Trump’s conversation with Comey.
"But the fact that the president made allusions to that — and then the White House would not confirm or deny it — is not anything that we've seen in recent days," Warner said.
"If there are tapes, will you try to subpoena them?" Stephanopoulos asked Warner.
"Absolutely," Warner responded. "First of all, we've got to make sure these tapes, if they exist, don't mysteriously disappear. So I've asked, others have asked, to make sure the tapes are preserved, if they exist."